Ameriphone Q90D is a versatile communication device that combines a TTY (text telephone) with a VCO (voice carry over) and text answering machine capabilities. With its PC-style keyboard and one-touch buttons for common phrases, it allows for efficient text communication. It also connects to compatible cellular phones and features a programmable personalized greeting and remote message retrieval for its answering machine function. Additionally, the built-in microphone enables hands-free VCO calls, while an optional speaker or headset can be used for HCO (hearing carry over) calls.